Packet loss computation in non-ESP flows

Carter Bullard carter at qosient.com
Mon Oct 1 14:34:37 EDT 2001


Hey Shilpa,
   Well, there are three basic mechanisms that argus
uses to report on packet loss/retransmission.  The
first is that argus has a complete TCP state machine
and is using that to determine drops and retransmitted
packets.  The second is to track monotonically
increasing sequence numbers when they exist.  Argus
does this with ESP and RTP flows.  And the third
scheme is to enforce symmetric reporting for strict
request/response protocols, so Argus, when run using
the -R option (response mode), Argus generates data
that allows for easy calculation of packets lost.
This mode allows for you to calculate drops for ICMP
echo, traceroute, dns, ntp, portmapper, netbios, etc ...

Carter

Carter Bullard
QoSient, LLC
300 E. 56th Street, Suite 18K
New York, New York  10022

carter at qosient.com
Phone +1 212 588-9133
Fax   +1 212 588-9134
http://qosient.com

> -----Original Message-----
> From: owner-argus-info at lists.andrew.cmu.edu 
> [mailto:owner-argus-info at lists.andrew.cmu.edu] On Behalf Of 
> Shilpa Bansod
> Sent: Monday, October 01, 2001 1:42 PM
> To: argus-info at lists.andrew.cmu.edu
> Subject: Packet loss computation in non-ESP flows
> 
> 
> Hi all,
> I have been trying to figure out how Argus computes packet 
> loss rate in
> non-ESP flows but have not been able to do so as yet. I would greatly
> appreciate any insight into this. 
> 
> Thanks!
> -Shilpa
> 
> 



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